The untold story of the rescue mission that could have been NASA's finest hour.

Shell game

There would be a number of activities that would be attempted for the first time during this conceptual inspection and rescue mission.

—Columbia Accident Investigation Board Report (Appendix D.13)

From here, the complexity of the mission begins to ratchet up to maximum. Depending on how tired and compromised they were physically, "CM1" and "CM2" could help spell the Atlantis pilot and commander at their station-keeping exercises (assuming that CM1 and CM2 were Columbia commander Rick Husband and pilot William McCool), but the two extra space suits would be put to considerable use.

Atlantis' two EVA crewmembers would remain outside, and while CM1 and CM2 were removing their suits, the two Atlantis crew would use their SAFER jet packs to check over Atlantis' tiles and leading edges for damage (Columbia lacked SAFER packs, and the inspection EVA its crew would have gone through would have involved much more strenuous techniques to clamber along the orbiter's structure and get a look at the wing).

CM1 and CM2 would remove their suits and then get them ready for reuse; they would be returned by EV1 and EV2 to Columbia and stashed in the airlock, which would then be pressurized and opened. Two more Columbia crewmembers would already have donned the spare suits shuttled over earlier and thus become CM3 and CM4, and the same procedure would be repeated as with CM1 and CM2.

Enlarge/ Another view of the crew transfer between Columbia and Atlantis.

NASA / CAIB Report, Appendix D.13

The report spells out a best-case scenario where the suit donning and doffing goes off without a hitch, and in that case, all the transfers could be done without stopping for a break. This would mean that Atlantis' EV1 and EV2 crewmembers would be outside for somewhere between 8.5 to nine hours in a single EVA.

However, that outcome is hardly a given. Putting on a space suit is a complex procedure on the ground, in full gravity and with multiple sharp-eyed assistants helping out. Putting on a suit in Columbia's middeck, possibly while still attempting to shake off the effects of carbon dioxide poisoning, is a much dicier operation. It's made even more complicated by the fact that for each successful crew transfer, the number of helpers is reduced. It's possible that the operation would have stretched to multiple EVAs—instead of nine hours, it could have taken more than three times as long.

After the first two two-person transfers, the next transfer would consist of a single person: CM5 would go across alone, with EV1 and EV2 assisting. This would be done because Columbia had a crew of seven, and one person would have to do the transfer by themselves. Leaving the last two crewmembers, CM6 and CM7, to operate as a pair at least meant that the two would have had each other's assistance in donning the well-used spacesuits. Ars consulted a number of sources to gauge the difficulty of donning spacesuits without any assistance from unsuited crew. Though none would speak on record, the consensus is that it would involve what was universally categorized as an extremely high degree of difficulty.

Shooting star

There would be no possibility of recovering Columbia.

—Columbia Accident Investigation Board Report (Appendix D.13)

Prior to their exit, the last two members of Columbia's crew would have some final tasks to carry out. The orbiter would need to be readied to be placed under ground control so that it could be deorbited.

There was no chance of recovery for the shuttle itself. Even if the wing could have been patched and cold-soaked and the shuttle's reentry profile altered to raise the reentry angle of attack and lower the temperature at the wing leading edge, it is unlikely that it would have survived. Further, even if successful reentry were possible, the shuttle could not be landed entirely from the ground—there was no way for Mission Control to have extended the shuttle's landing gear or the air probes necessary to judge velocity once in the atmosphere. Those functions (as well as starting the shuttle's auxiliary power unit) could only be invoked by physically throwing switches in the cockpit during approach and landing.

The remaining shuttle fleet gained the ability to land totally under ground control in 2006, with the development of the RCO IFM cable, a 28-foot (8.5-meter) braided cable that the crew could use to physically link the cockpit with the shuttle's avionics bay and patch Mission Control into the required switches.

Enlarge/ The landing gear switches (left) are in front of the commander's station. They are among the few systems that could not be operated remotely by ground control.

Steven Michael

For Columbia, this wasn't an option. CM6 and CM7 would have had to proceed to the shuttle's flight deck and toggle a number of switches into place, giving Mission Control on the ground direct command of Columbia's guidance and maneuvering systems.

CM6 and CM7 would then depart, sealing the airlock behind them and leaving Columbia to find its own way home. Atlantis would back slowly away from its sister ship, and its crew of 11 would busy themselves preparing for their own crowded reentry ordeal—never before has an orbiter landed with 11 crewmembers, and even simple things like seating would be complicated. Some crew would literally have to sit strapped to the floor during reentry.

At some point over the next few hours or days, ground controllers would command Columbia to close its cargo bay doors and orient itself for what would be its final task. The shuttle would roll its damaged thermal tiles to face Earth and perform a retrograde burn with its large OMS engines. Shortly after that, it would cross the entry interface.

Contrary to popular belief, the heat a spacecraft faces on reentry isn't generated by simple friction but rather by ram pressure—the fast-moving shuttle compresses the air in front of it, forming a massive shock zone in which air molecules ionize and break apart. As Columbia descended, an observer on the flight deck would see the windows glow and flare with plasma. After a short time, that plasma would invade the shuttle's structure through the hole in its wing.

Columbia's last act would be to brighten the sky over the South Pacific, first as one glowing star and then breaking apart into many. The remains of the oldest shuttle would pepper the surface of the Pacific, and it would be no more.

Enlarge/ Glowing, ionized trail from Atlantis' re-entry on the final flight of the space shuttle program. Photographed from the ISS on July 21, 2011.

NASA

Ad astra per aspera

It should be noted that although each of the individual elements could be completed in a best-case scenario to allow a rescue mission to be attempted, the total risk of shortening training and preparation time is higher than the individual elements.

—Columbia Accident Investigation Board Report (Appendix D.13)

We all love Hollywood endings, but it's difficult to envision the rescue mission coming together with the required level of perfection. For example, in researching this article, I was unable to discover the number of times a shuttle has gone through an Orbital Processing Facility, Vehicle Assembly Building, and launch pad processing flow with no errors or faults. Based on the complexity of the machine, I suspect that it has never happened before.

Further Reading

Apollo vet Sy Liebergot shows Ars how NASA got men safely to the Moon and back.

And yet, when faced with a challenge of this magnitude and with such tremendous consequences, it's incredibly attractive to imagine NASA rising to the task. As an agency, NASA simultaneously represents the best and worst of the United States of America—it is responsible for some of the greatest engineering achievements in the history of humankind and has accomplished a long list of goals originally deemed impossible. At the same time, the agency is also crippled by a lack of direction and leadership; it has gone from being an organization capable of putting human beings on other worlds to an organization that lacks even the means to put them into low Earth orbit without assistance.

The mission to rescue Columbia, though, represents the kind of task that NASA, since its beginnings, has demonstrated an unswerving ability to execute. There would have been a clear goal, there would have been hard timing requirements, and the agency's massive pool of engineering talent would be empowered to accomplish the goal at any cost and without restriction.

The will to win would not be lacking, but technical challenges are ignorant of will and drive—look, for example, at the liquid oxygen tank explosion that crippled the Apollo 13 command and service module in 1970. That explosion was the result of a combination of events that occurred prior to launch, with potential blame stretching from the tank's manufacturer all the way to the crew itself. The error-free rescue of Columbia would have depended not just on the flawless execution of teams at all of the NASA centers but also on an unknown number of events that happened days, weeks, months, or even years in the past leading up to the mission.

In researching this article, I spoke with a large number of current and former NASA personnel, both inside and outside of the Missions Operation Directorate. All were polite, but none would talk on-record about the feasibility of the proposed Atlantis rescue mission. The formal response I received from NASA's Public Affairs Office respectfully but firmly informed me that the CAIB report is NASA's full and official statement on the matter:

From NASA’s standpoint, there is nothing further to add to the Columbia Accident Investigation Report (Chapter six and its appendices) related to the "what if" scenario of rescuing the STS-107 crew. As you are aware, it is spelled out very clearly that there would have to have been a very large number of "knowns" to have executed a rescue or repair mission for Columbia at that time.

...

Beyond that, we respectfully decline any specific interviews on the subject and reference you to the CAIB report for the detailed analysis provided during the investigation of the Columbia accident.

Ultimately, Appendix D.13 is a well-informed, research-backed exercise in speculation, constructed by engineers who were intimately familiar with shuttle program operations. My telling of the rescue's story is not intended to criticize or damn NASA for its actions, nor am I attempting from a position of historical privilege to second guess the decision-makers who to this day must live with the grave consequences of the choices made. Columbia and its crew almost certainly could not have been rescued without too many "ifs" having fallen the other way. I can tell the story of what might have been the most awe-inspiring moment in all of human space flight, but I am profoundly unqualified to speculate beyond the boundaries of the CAIB report.

It's an amazing story—but it's only a story.

The long road back

It is unlikely that launching a space vehicle will ever be as routine an undertaking as commercial air travel—certainly not in the lifetime of anybody who reads this. The scientists and engineers continually work on better ways, but if we want to continue going into outer space, we must continue to accept the risks.

—Columbia Accident Investigation Board Report

It took 907 days after Columbia's destruction for NASA to return to flight. STS-114—flown by Discovery instead of Atlantis—lifted off from the Cape on July 26, 2005. I remember it very well—now as a not-so-junior system administrator, I watched helplessly as the sheer number of Boeing employees streaming the countdown and launch video from NASA TV saturated our site's Internet link, which somewhat hilariously almost caused site management to try to request a launch hold (Boeing's Houston office provided shuttle support, and some of those support activities needed that same Internet link to function). The launch was a success.

Starting with STS-114, no shuttle would fly without a rescue shuttle on standby. These planned emergency flights (numbered STS-3xx) were called LON missions, for "Launch On Need." In the event of trouble on a shuttle mission, crews would rendezvous with the ISS and shelter there for up to 50 days, while the LON shuttle would be made ready to fly to retrieve them.

The one exception to this was the final Hubble servicing mission, STS-125. The orbital height and inclination of the Hubble made the mission totally incompatible with an emergency ISS rendezvous in the event of trouble, so a plan based partially on the Atlantis/Columbia rescue was drafted. The STS-125 LON mission would have been dubbed STS-400. Because the ISS wasn't available, STS-400's Endeavour needed to be ready to launch on short notice; this led to the final instance of what was already a rare sight: two shuttles staged at LC-39 simultaneously.

The LON missions were never needed, and the shuttle program finished without any other significant incidents. Foam strikes were not eliminated, but post-launch analysis of each shuttle was increased. It is a virtual certainty that future NASA manned spacecraft will return to their rightful place on top of launch vehicles rather than being slung on their sides. NASA's culture continues to evolve; it is impossible to say at this point if the lessons of Columbia have been fully inculcated into the agency.

I was there for the aftermath and the return to flight, but agency-wide policy changes are things that happened far above my pay grade. The thing I remember more than anything else, the single most vivid memory of them all, is of the memorial service the Tuesday after Columbia's destruction.

February 4, 2003

This cause of exploration and discovery is not an option we choose—it is a desire written in the human heart. We are that part of creation which seeks to understand all creation. We find the best among us, send them forth into unmapped darkness, and pray they will return. They go in peace for all mankind, and all mankind is in their debt.

We arrived at the Johnson Space Center at about 9:30am, having been told that space would be limited for the service, which was to start at noon. After a half-mile of walking and a security checkpoint, we stood in the central mall by Building 16, lost amid a sea of people. The stage and podium were far away on the other side of the grassy field, and we passed the two-and-a-half hours in uncomfortable, standing silence. After a long wait, Air Force One, trailed by three F-15s, circled on its way down to Ellington Field. The crowd swelled to its maximum just after 11. At noon, with no fanfare, President Bush and First Lady Laura Bush walked together to their place on the stage. They held hands, which stuck in my mind—even the most powerful man in the world holds hands with his wife.

There was an invocation, and then words from NASA's director and the chief of the Astronaut Corps. Both paid tribute to each astronaut individually, and the Corps chief clearly had to fight to keep back tears. The president stepped to the podium next and spoke eloquently about the human spirit. The only even vaguely political words that left his mouth were ultimately topical—he said that the space program would continue. Then he, too, spoke of each astronaut individually, praising their daring and dedication.

A ship's bell tolled seven times, once for each of Columbia's crew, and then four NASA T-38s flew over in the missing man formation. The jets moved in low and fast, streaking toward us in a wedge less than 250 feet off the ground. As they passed overhead, the second jet back on the left side of the formation peeled sharply upward, right as the roar of the engines hammered at us. The missing man jet arched high and straight as the formation continued onward, now with an empty spot to recognize that there were men and women who were no longer with us.

I have never before witnessed anything so profoundly moving as that trio of jets hurtling low over the rest of the campus, with their missing comrade thousands of feet above and rocketing higher still. I will remember it forever.

Promoted Comments

I worked on the planning for the STS-125 rescue mission, STS-400. It took 18 months of planning to develop the procedures, modify the tools, test and simulate the GN&C, EVA, and robotics choreography, and prepare all the paperwork to satisfy everyone that it was a safe plan for both orbiters and the crew. The proposed plan in this article would have been even more difficult because there was no opportunity to use the RMS (robotic arm) to grapple Columbia. Columbia wasn't carrying an arm, and Columbia itself did not have a grapple fixture that Atlantis's arm could use. I am extremely dubious that the manual station keeping would be doable even just from a propellant standpoint: STS-400 had the crew transfer requiring two days. (The STS-400 timeline is available online) For Columbia, that would mean manually station-keeping for an entire EVA (6.5 hours), then separating until the next EVA is ready, and performing another rendezvous and station keeping for > 6.5 hours. I don't think there is anywhere near enough RCS fuel to do that.

The only hope that this plan would have ever had would have been if the plan had already been in place prior to Columbia's launch, as there is no way on this Earth that NASA would have approved a flight with untested procedures that could destroy both orbiters. As I said above, the very similar STS-400 flight planning took 18 months; even if the entire NASA work force worked around the clock, that amount of work wasn't going to happen in just a few weeks. Sadly, I can't see a path where this would have actually been feasible.

Why not roll Columbia 90 degrees, so that Atlantis can be at the same altitude? Wouldn't that make station-keeping easier? Is a space shuttle simply unstable enough in any other orbital attitude that the described attitude is the only feasible one?

I'm no rocket scientist, but my guess is that would make Atlantis' approach much more complex. Beyond that, I don't know. Perhaps @STS_Engineer might be able to contribute a good answer, though.

I'll try!

There are three main reasons for a particular attitude to be chosen for a Shuttle: Thermal regulation (which parts are getting heated by the sun), communications (The K-band antenna has to be able to point to the TDRS satellites), and fuel conservation (a gravity gradient or Torque Equilibrium attitude will minimize jet firings to maintain attitude). To maximize the Columbia's consumables, it would have been placed in a gravity gradient attitude, probably with a slow roll for thermal considerations, and they would have worked around the spotty communications.

For two orbiters to be in exactly the same orbit, so as to minimize the need to fire jets for stationkeeping, they have to be aligned with their centers of mass at exactly the same altitude and inline with the direction of motion in orbit. Unfortunately, the Shuttle center of mass is near the rear and bottom of the payload bay. The necessities of performing the EVA transfers absolutely requires the two orbiter have their payload bays facing each other. The necessity of having to fire jets to approach and leave absolutely requires that the nose or tail not overlap, otherwise the jet firing would bath the payload bay and the airlock with toxic fuel. For these reasons, the only way for two orbiters to approach each other is at the exact 90 degree attitude that Lee described in the article. It's exactly how STS-400's rendezvous was planned, but since we had the arm as a physical attachment between the orbiters, we could use it to re-align the orbiters after grappling so that the payload bays lined up. We could then use only the tail jets on STS-400, and move both orbiters together for attitude control.

In the article's scenario, you need fine attitude control all of the time, so you need both tail and nose jets. You have to keep the 90 degree attitude. So, couldn't we just arrange it so that both centers of mass were at the same altitude but keep the 90 degree offset? Yes, but then you have the Columbia no longer in a stable gravity gradient attitude. It would look like an open pair of scissors balanced of their tips.To maintain that attitude, BOTH orbiters would have to be under active manual attitude control, and two orbiters that close together, both firing their jets, is a recipe for disaster.

Lee Hutchinson / Lee is the Senior Reviews Editor at Ars and is responsible for the product news and reviews section. He also knows stuff about enterprise storage, security, and manned space flight. Lee is based in Houston, TX.